Titanium oxide may exist in a rutile crystal structure or an anatase crystal structure. The crystalline type of the titanium oxide may be established by the production method utilized to form the titanium oxide. Rutile-type titanium oxide is formed by deposition of the titanium oxide at temperatures of at least about 660° C., while anatase-type titanium oxide typically results from deposition processes maintained at or below temperatures of 465° C. Deposition processes having temperatures between 465° C. and 660° C. generally form mixtures of rutile-type titanium oxide and anatase-type titanium oxide. Some methods have been developed which form anatase-type titanium oxide at low deposition temperatures, and then utilize high temperature annealing to convert the anatase-type titanium oxide into rutile-type titanium oxide.
Rutile-type titanium oxide may be preferred over anatase-type titanium oxide in some applications because of the very high dielectric constant of the rutile-type titanium oxide (k>100). For instance, rutile-type titanium oxide may be preferred over anatase-type titanium oxide for utilization as capacitor dielectric material of integrated circuitry (for instance, as the capacitor dielectric material utilized in dynamic random access memory [DRAM]). Unfortunately, the high temperatures utilized in conventional methods of forming rutile-type titanium oxide may be damaging to various integrated circuit components. Accordingly, it can be difficult to incorporate rutile-type titanium oxide into integrated circuitry utilizing conventional methods of forming rutile-type titanium oxide.
For the above-discussed reasons, it would be desirable to develop new methods for forming rutile-type titanium oxide.